Valve as in type, but the keel puncta are 5 in 10 µ and the striæ are 11-12 in 10 µ. L. 71 µ.
H. amphioxys var. major Grun. is stated to be 120 µ in length. The present form is smaller but corresponds in puncta and striation. Van Heurck remarks that it approaches H. virgata.
Abundant in sand ripples on the beach at Cape May, N. J.
Pl. [39], Fig. 4.
Fig. 6, Pl. [39], is drawn from an authentic specimen of Wm. Smith's Nitzschia amphioxys, from England, and is introduced for comparison. The central nodule is not evident.
Fig. 3, Pl. [39], is from a specimen from an unknown locality. The keel puncta are 6 and the striæ 16 in 10 µ.
HANTZSCHIA VIRGATA (ROPER) GRUN.
Valve arcuate on the dorsal side, nearly straight on the ventral side, with rostrate, recurved apices; keel puncta prolonged to one-third the width of the valve, 4 in 10 µ; transverse striæ, 9-10 in 10 µ. L. 115 µ.
Shark River, N. J. (Kain).
I have not been able to find this form on our coast. The figure is drawn from a specimen from another locality.